1. Field of the Invention
The present invention relates to a semiconductor device and to a method for fabricating a semiconductor device using the same. More specifically, the present invention relates to an apparatus for cleaning a semiconductor wafer and to a method for cleaning a wafer using the same.
2. Description of the Related Art
Semiconductor devices are ordinarily cleaned using cleaning solutions such as standard cleaning 1 (a mixed solution of hydrogen peroxide, ammonium hydroxide and deionized water), hydrofluoric acid (HF) and a sulfuric peroxide mixture (SPM). These conventional cleaning solutions contain strong chemicals that cause corrosion of a metal layer of the semiconductor device. Therefore, it is necessary to develop new cleaning solutions with the cleaning ability of the conventional solutions but which minimize corrosion of the metal layer.
Ozone water, hydrogen water, and electrolytic-ionized water have recently been studied as cleaning solutions capable of meeting this need. The ozone water and the hydrogen water cleaning solutions are used by dissolving an ozone gas or a hydrogen gas, respectively, that occurs as a result of electrolyzing deionized water, in the deionized water. The electrolytic-ionized water cleaning solution is used by oxidation water and reduction water that occur as a result of electrolyzing deionized water. In the ozone water, the hydrogen water, and the electrolytic-ionized water, it is advantageous to comparatively free control pH and oxidation-reduction potential by using a gas dissolved in the solution or by an electrolytic current during electrolysis. The ozone water, the hydrogen water, and the electrolytic-ionized water can each remove impurities without corrosion of the metal layer using pH and oxidation-reduction potential.
However, the cleaning ability of the ozone water, the hydrogen water, or the electrolytic-ionized water is minor when used at a normal temperature. Raising the temperature of the ozone water, the hydrogen water, or the electrolytic-ionized water increases its cleaning ability. However, if the ozone water, the hydrogen water, or the electrolytic-ionized water is heated for too long or left alone in the opened state, gases in the cleaning solution evaporate shortening the lifespan of the cleaning solution. Also, because heating the ozone water, the hydrogen water, or the electrolytic-ionized water for a long time dramatically reduces its cleaning ability, it is necessary to heat the cleaning solution rapidly, and to use the heated cleaning solution immediately after heating to clean the wafer.
In order to solve the aforementioned problems, it is a feature of an embodiment of the present invention to provide an apparatus for cleaning a semiconductor wafer by heating a cleaning solution for a short time.
It is another feature of an embodiment of the present invention to provide a method for cleaning a wafer using the apparatus for cleaning a semiconductor wafer.
In an effort to provide for these and other features of the present invention, there is provided an apparatus for cleaning a semiconductor wafer, which includes a chamber on which a wafer is mounted; a revolving chuck mounted in the chamber for supporting and fixing the wafer; a nozzle for spraying cleaning solution onto the wafer, wherein the cleaning solution may be ozone water, hydrogen water, or electrolytic-ionized water; a cover for covering an upper part of the chamber; a heating lamp which is fixed on an upper part of the cover for heating the wafer or the cleaning solution and which may be an ultraviolet or an infrared, rod-shaped lamp having a length equal to the radius of the wafer; a cooling water conduit surrounding the cover; and an antipollution plate which is preferably made of transparent quartz or sapphire mounted on a lower part of the heating lamp in the cover for preventing the heating lamp from being polluted by the cleaning solution.
In accordance with another feature of the present invention, there is provided an apparatus for cleaning a semiconductor wafer, which includes a chamber on which a wafer is mounted; a revolving chuck mounted in the chamber for supporting and fixing the wafer; a nozzle for spraying cleaning solution onto the wafer, the cleaning solution may be ozone water, hydrogen water, or electrolytic-ionized water; a cover for covering an upper part of the chamber; a laser fixed on an upper part of the cover for heating the wafer or the cleaning solution, the laser may be an ultraviolet, an infrared, or a visible ray laser; and a focusing lens for condensing a beam emitted from the laser onto the wafer.
The apparatus may further include an antipollution plate preferably made of transparent quartz or sapphire mounted on a lower part of the focusing lens in the cover for preventing the focusing lens from being polluted by the cleaning solution.
In accordance with another feature of the invention there is provided a method for cleaning a wafer including providing one of the above-described apparatuses for cleaning a semiconductor wafer; rotating a wafer at a predetermined speed; spraying cleaning solution of ozone water, hydrogen water, or electrolytic-ionized water onto the wafer through a nozzle; heating the wafer or the cleaning solution by a heating lamp or a laser, depending on the apparatus used; and cleaning the wafer.
These and other features of the present invention will be readily apparent to those of ordinary skill in the art upon review of the detailed description that follows.